Question

which atmospheric gas is being described? a noble gas (non - reactive), makes up approximately 1% of the atmosphere, third most common gas in air hydrogen argon methane oxygen

Explanation:

Argon is a noble gas, non - reactive, makes up about 1% of the atmosphere and is the third most common gas in air. Hydrogen is not a major atmospheric gas in these proportions. Methane is a trace gas and not a noble gas. Oxygen is reactive and is the second most common gas.

Answer:

B. argon